There are many applications where it is desired to use a driver circuit with a bipolar or field-effect transistor output stage to drive a high power pulsed semiconductor laser diode. Laser diodes typically operate with an electrical pulse of 4 volts potential, 60 amperes current, 50 nanoseconds duration, and a repetition rate of 200,000 pulses per second. The best conventional packages heretofore have approximately 10 nanohenries inductance in series with 40 milliohms resistance. Therefore 30 volts must be applied to obtain the desired maximum rise time of 20 nanoseconds, neglecting the effects of the lead from the driver to the laser package. High voltage thyristor output stages can be used to drive laser diodes in the conventional packages since they can overcome the inductance with higher voltages. Unfortunately, high pulse repetition rates cannot be achieved with a thyristor output stage.
Therefore, there has been needed a package which efficiently couples a laser diode to a transmission line having greatly differing characteristic impedance while still providing sufficient heat sinking that the laser diode can be operated at high current levels and high repetition rates.